What concerns do I need to look into when running a high current alternator?

[greymouser7]

I want to install a large sterio system in my Road Runner.

I understand that I need to provide a capicitor for bass speakers.

My concerns are the danger/operability of the ignition and charging systems while driving (wires {size}, grounding). The powermaster alternators that output above 100 amps appear to be one wire systems and currently the car has the original electronic ignition with the external voltage regulator.

I do not believe that I have an amp meter-but would it be possible to fry somthing in the dash behind the gauge cluster?

I was taught that the loads on the electrical system only draw as much current as they need-but I am concerned with the output of a high amp alternator when there isn't a significant load {alternator temp?} OR a very large load.

It needs to supply ignition (accel super coil in the future with a MSD box), battery charging, wipers, headlights, (no electronic fuel pump for now-nor ever any electronic water pumps) air conditioning, speakers: 12's X2, 10's X2, and 8 smaller speakers & a 500 watt amp.

The current stock system seems barely adequate to operate the vehicle with head lights and wipers on.

I live in a extremely humid environment with a significant amount of salt in the air. Of the previous cheap cars that I have owned here on the coast of South Georgia, grounding wires and battery terminals require cleaning annually and I do well to coat the top of them with a di-electric grease.

Some of the vehicles drew current from the battery when the A/C, headlights, wipers were all on leaving me stranded when the car was turned off (until I figured it out).

-Thanks FABO for your help!

 

[KitCarlson]

Sound like you have considered many things. Since the OEM alternator wiring was most likely designed for a 40 to 60 amp system you will need to fix that. One way to do that would be to add a second cable to the 100 amp alternator with fuse and high current relay so it is powered only when in the accessory position. Since the 500W stereo is about 42 Amps at 12V you need to design wire size for more than that.

It is also a good idea to work over voltage drop issues on the original wiring and do the amp meter bypass modification. Without the engine running the feed will come from existing wiring. It would be best to beef up wire sizes, and limitations like bulkhead connector terminal ratings.

To run the 100 amp alternator may require 2 pulleys, so there may be work with that unless that already exists.

 

[67Dart273]

It's not clear to me whether the ammeter in your car has been eliminated or not. Please read this article on the subject:

http://www.madelectrical.com/electricaltech/amp-gauges.shtml

You need to modify the wiring if it has not been, and run the alternator output DIRECTLY to the battery with about a no 6 wire.

Pull all loads off the battery or starter relay stud, and make sure they are properly fused/ breaker protected as close to the battery as you can get.

Some of us have removed our ammeters and "converted" them to voltmeters. This will vary with your skill and the car, but in the case of my Dart, it was VERY easy, an afternoon project:

http://www.forabodiesonly.com/mopar/showthread.php?t=119480&highlight=ammeter+conversion

My Dart dash is like the one shown near the top of page 3 of that thread. A Sunpro voltmeter for 20 bucks, mounted in place of the ammeter, and the adjustment pot set so that 14V is centered on the original scale. I didn't even bother to glue the old needle on, just left the Sunpro needle as is.